[Intel-gfx] [PATCH 9/9] drm/i915: Add two-stage ILK-style watermark programming (v7)

Matt Roper matthew.d.roper at intel.com
Mon Nov 30 16:08:34 PST 2015


On Wed, Nov 25, 2015 at 07:08:53PM +0200, Ville Syrjälä wrote:
> On Wed, Nov 25, 2015 at 08:48:35AM -0800, Matt Roper wrote:
> > In addition to calculating final watermarks, let's also pre-calculate a
> > set of intermediate watermark values at atomic check time.  These
> > intermediate watermarks are a combination of the watermarks for the old
> > state and the new state; they should satisfy the requirements of both
> > states which means they can be programmed immediately when we commit the
> > atomic state (without waiting for a vblank).  Once the vblank does
> > happen, we can then re-program watermarks to the more optimal final
> > value.
> > 
> > v2: Significant rebasing/rewriting.
> > 
> > v3:
> >  - Move 'need_postvbl_update' flag to CRTC state (Daniel)
> >  - Don't forget to check intermediate watermark values for validity
> >    (Maarten)
> >  - Don't due async watermark optimization; just do it at the end of the
> >    atomic transaction, after waiting for vblanks.  We do want it to be
> >    async eventually, but adding that now will cause more trouble for
> >    Maarten's in-progress work.  (Maarten)
> >  - Don't allocate space in crtc_state for intermediate watermarks on
> >    platforms that don't need it (gen9+).
> >  - Move WaCxSRDisabledForSpriteScaling:ivb into intel_begin_crtc_commit
> >    now that ilk_update_wm is gone.
> > 
> > v4:
> >  - Add a wm_mutex to cover updates to intel_crtc->active and the
> >    need_postvbl_update flag.  Since we don't have async yet it isn't
> >    terribly important yet, but might as well add it now.
> >  - Change interface to program watermarks.  Platforms will now expose
> >    .initial_watermarks() and .optimize_watermarks() functions to do
> >    watermark programming.  These should lock wm_mutex, copy the
> >    appropriate state values into intel_crtc->active, and then call
> >    the internal program watermarks function.
> > 
> > v5:
> >  - Skip intermediate watermark calculation/check during initial hardware
> >    readout since we don't trust the existing HW values (and don't have
> >    valid values of our own yet).
> >  - Don't try to call .optimize_watermarks() on platforms that don't have
> >    atomic watermarks yet.  (Maarten)
> > 
> > v6:
> >  - Rebase
> > 
> > v7:
> >  - Further rebase
> > 
> > Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> > Reviewed-by(v5): Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_drv.h      |   6 +-
> >  drivers/gpu/drm/i915/intel_atomic.c  |   1 +
> >  drivers/gpu/drm/i915/intel_display.c |  90 +++++++++++++++++++-
> >  drivers/gpu/drm/i915/intel_drv.h     |  31 ++++++-
> >  drivers/gpu/drm/i915/intel_pm.c      | 160 ++++++++++++++++++++++++-----------
> >  5 files changed, 232 insertions(+), 56 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > index 5172604..427b488 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -630,7 +630,11 @@ struct drm_i915_display_funcs {
> >  			  struct dpll *best_clock);
> >  	int (*compute_pipe_wm)(struct intel_crtc *crtc,
> >  			       struct drm_atomic_state *state);
> > -	void (*program_watermarks)(struct intel_crtc_state *cstate);
> > +	int (*compute_intermediate_wm)(struct drm_device *dev,
> > +				       struct intel_crtc *intel_crtc,
> > +				       struct intel_crtc_state *newstate);
> > +	void (*initial_watermarks)(struct intel_crtc_state *cstate);
> > +	void (*optimize_watermarks)(struct intel_crtc_state *cstate);
> >  	void (*update_wm)(struct drm_crtc *crtc);
> >  	int (*modeset_calc_cdclk)(struct drm_atomic_state *state);
> >  	void (*modeset_commit_cdclk)(struct drm_atomic_state *state);
> > diff --git a/drivers/gpu/drm/i915/intel_atomic.c b/drivers/gpu/drm/i915/intel_atomic.c
> > index 643f342..b91e166 100644
> > --- a/drivers/gpu/drm/i915/intel_atomic.c
> > +++ b/drivers/gpu/drm/i915/intel_atomic.c
> > @@ -95,6 +95,7 @@ intel_crtc_duplicate_state(struct drm_crtc *crtc)
> >  
> >  	crtc_state->update_pipe = false;
> >  	crtc_state->disable_lp_wm = false;
> > +	crtc_state->wm.need_postvbl_update = false;
> >  
> >  	return &crtc_state->base;
> >  }
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index eb52afa..8db0486 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -11801,6 +11801,12 @@ int intel_plane_atomic_calc_changes(struct drm_crtc_state *crtc_state,
> >  		intel_crtc->atomic.update_wm_pre = true;
> >  	}
> >  
> > +	/* Pre-gen9 platforms need two-step watermark updates */
> > +	if ((intel_crtc->atomic.update_wm_pre || intel_crtc->atomic.update_wm_post) &&
> > +	    INTEL_INFO(dev)->gen < 9 &&
> > +	    dev_priv->display.optimize_watermarks)
> > +		to_intel_crtc_state(crtc_state)->wm.need_postvbl_update = true;
> > +
> >  	if (visible || was_visible)
> >  		intel_crtc->atomic.fb_bits |=
> >  			to_intel_plane(plane)->frontbuffer_bit;
> > @@ -11957,8 +11963,29 @@ static int intel_crtc_atomic_check(struct drm_crtc *crtc,
> >  	ret = 0;
> >  	if (dev_priv->display.compute_pipe_wm) {
> >  		ret = dev_priv->display.compute_pipe_wm(intel_crtc, state);
> > -		if (ret)
> > +		if (ret) {
> > +			DRM_DEBUG_KMS("Target pipe watermarks are invalid\n");
> >  			return ret;
> > +		}
> > +	}
> > +
> > +	if (dev_priv->display.compute_intermediate_wm &&
> > +	    !to_intel_atomic_state(state)->skip_intermediate_wm) {
> > +		if (WARN_ON(!dev_priv->display.compute_pipe_wm))
> > +			return 0;
> > +
> > +		/*
> > +		 * Calculate 'intermediate' watermarks that satisfy both the
> > +		 * old state and the new state.  We can program these
> > +		 * immediately.
> > +		 */
> > +		ret = dev_priv->display.compute_intermediate_wm(crtc->dev,
> > +								intel_crtc,
> > +								pipe_config);
> > +		if (ret) {
> > +			DRM_DEBUG_KMS("No valid intermediate pipe watermarks are possible\n");
> > +			return ret;
> > +		}
> >  	}
> >  
> >  	if (INTEL_INFO(dev)->gen >= 9) {
> > @@ -13409,6 +13436,7 @@ static int intel_atomic_commit(struct drm_device *dev,
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> >  	struct drm_crtc_state *crtc_state;
> >  	struct drm_crtc *crtc;
> > +	struct intel_crtc_state *intel_cstate;
> >  	int ret = 0;
> >  	int i;
> >  	bool any_ms = false;
> > @@ -13500,6 +13528,20 @@ static int intel_atomic_commit(struct drm_device *dev,
> >  
> >  	drm_atomic_helper_wait_for_vblanks(dev, state);
> >  
> > +	/*
> > +	 * Now that the vblank has passed, we can go ahead and program the
> > +	 * optimal watermarks on platforms that need two-step watermark
> > +	 * programming.
> > +	 *
> > +	 * TODO: Move this (and other cleanup) to an async worker eventually.
> > +	 */
> > +	for_each_crtc_in_state(state, crtc, crtc_state, i) {
> > +		intel_cstate = to_intel_crtc_state(crtc->state);
> > +
> > +		if (dev_priv->display.optimize_watermarks)
> > +		    dev_priv->display.optimize_watermarks(intel_cstate);
> > +	}
> > +
> >  	mutex_lock(&dev->struct_mutex);
> >  	drm_atomic_helper_cleanup_planes(dev, state);
> >  	mutex_unlock(&dev->struct_mutex);
> > @@ -13862,13 +13904,44 @@ static void intel_begin_crtc_commit(struct drm_crtc *crtc,
> >  				    struct drm_crtc_state *old_crtc_state)
> >  {
> >  	struct drm_device *dev = crtc->dev;
> > +	struct drm_i915_private *dev_priv = to_i915(dev);
> >  	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> > +	struct intel_crtc_state *cstate = to_intel_crtc_state(crtc->state);
> >  	struct intel_crtc_state *old_intel_state =
> >  		to_intel_crtc_state(old_crtc_state);
> >  	bool modeset = needs_modeset(crtc->state);
> >  
> > -	if (intel_crtc->atomic.update_wm_pre)
> > +	/*
> > +	 * IVB workaround: must disable low power watermarks for at least
> > +	 * one frame before enabling scaling.  LP watermarks can be re-enabled
> > +	 * when scaling is disabled.
> > +	 *
> > +	 * WaCxSRDisabledForSpriteScaling:ivb
> > +	 */
> > +	if (cstate->disable_lp_wm) {
> > +		ilk_disable_lp_wm(crtc->dev);
> > +		intel_wait_for_vblank(crtc->dev, intel_crtc->pipe);
> > +	}
> > +
> > +	/*
> > +	 * For platforms that support atomic watermarks, program the
> > +	 * 'intermediate' watermarks immediately.  On pre-gen9 platforms, these
> > +	 * will be the intermediate values that are safe for both pre- and
> > +	 * post- vblank; when vblank happens, the 'active' values will be set
> > +	 * to the final 'target' values and we'll do this again to get the
> > +	 * optimal watermarks.  For gen9+ platforms, the values we program here
> > +	 * will be the final target values which will get automatically latched
> > +	 * at vblank time; no further programming will be necessary.
> > +	 *
> > +	 * If a platform hasn't been transitioned to atomic watermarks yet,
> > +	 * we'll continue to update watermarks the old way, if flags tell
> > +	 * us to.
> > +	 */
> > +	if (dev_priv->display.initial_watermarks != NULL) {
> > +		dev_priv->display.initial_watermarks(cstate);
> > +	} else if (intel_crtc->atomic.update_wm_pre) {
> >  		intel_update_watermarks(crtc);
> > +	}
> >  
> >  	/* Perform vblank evasion around commit operation */
> >  	intel_pipe_update_start(intel_crtc);
> > @@ -14207,6 +14280,7 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
> >  	intel_crtc->cursor_size = ~0;
> >  
> >  	intel_crtc->wm.cxsr_allowed = true;
> > +	mutex_init(&intel_crtc->wm.wm_mutex);
> >  
> >  	BUG_ON(pipe >= ARRAY_SIZE(dev_priv->plane_to_crtc_mapping) ||
> >  	       dev_priv->plane_to_crtc_mapping[intel_crtc->plane] != NULL);
> > @@ -15136,7 +15210,7 @@ static void sanitize_watermarks(struct drm_device *dev)
> >  	int i;
> >  
> >  	/* Only supported on platforms that use atomic watermark design */
> > -	if (!dev_priv->display.program_watermarks)
> > +	if (!dev_priv->display.optimize_watermarks)
> >  		return;
> >  
> >  	/*
> > @@ -15148,6 +15222,13 @@ static void sanitize_watermarks(struct drm_device *dev)
> >  	if (WARN_ON(IS_ERR(state)))
> >  		return;
> >  
> > +	/*
> > +	 * Hardware readout is the only time we don't want to calculate
> > +	 * intermediate watermarks (since we don't trust the current
> > +	 * watermarks).
> > +	 */
> > +	to_intel_atomic_state(state)->skip_intermediate_wm = true;
> > +
> >  	ret = intel_atomic_check(dev, state);
> >  	if (ret) {
> >  		/*
> > @@ -15163,7 +15244,8 @@ static void sanitize_watermarks(struct drm_device *dev)
> >  	for_each_crtc_in_state(state, crtc, cstate, i) {
> >  		struct intel_crtc_state *cs = to_intel_crtc_state(cstate);
> >  
> > -		dev_priv->display.program_watermarks(cs);
> > +		cs->wm.need_postvbl_update = true;
> > +		dev_priv->display.optimize_watermarks(cs);
> >  	}
> >  
> >  	drm_atomic_state_free(state);
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index 8fae824..c53eb10 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -249,6 +249,12 @@ struct intel_atomic_state {
> >  	bool dpll_set;
> >  	struct intel_shared_dpll_config shared_dpll[I915_NUM_PLLS];
> >  	struct intel_wm_config wm_config;
> > +
> > +	/*
> > +	 * Current watermarks can't be trusted during hardware readout, so
> > +	 * don't bother calculating intermediate watermarks.
> > +	 */
> > +	bool skip_intermediate_wm;
> >  };
> >  
> >  struct intel_plane_state {
> > @@ -491,13 +497,29 @@ struct intel_crtc_state {
> >  
> >  	struct {
> >  		/*
> > -		 * optimal watermarks, programmed post-vblank when this state
> > -		 * is committed
> > +		 * Optimal watermarks, programmed post-vblank when this state
> > +		 * is committed.
> >  		 */
> >  		union {
> >  			struct intel_pipe_wm ilk;
> >  			struct skl_pipe_wm skl;
> >  		} optimal;
> > +
> > +		/*
> > +		 * Intermediate watermarks; these can be programmed immediately
> > +		 * since they satisfy both the current configuration we're
> > +		 * switching away from and the new configuration we're switching
> > +		 * to.
> > +		 */
> > +		struct intel_pipe_wm intermediate;
> > +
> > +		/*
> > +		 * Platforms with two-step watermark programming will need to
> > +		 * update watermark programming post-vblank to switch from the
> > +		 * safe intermediate watermarks to the optimal final
> > +		 * watermarks.
> > +		 */
> > +		bool need_postvbl_update;
> >  	} wm;
> >  };
> >  
> > @@ -587,8 +609,12 @@ struct intel_crtc {
> >  			struct intel_pipe_wm ilk;
> >  			struct skl_pipe_wm skl;
> >  		} active;
> > +
> >  		/* allow CxSR on this pipe */
> >  		bool cxsr_allowed;
> > +
> > +		/* Protects active and need_postvbl_update */
> > +		struct mutex wm_mutex;
> >  	} wm;
> >  
> >  	int scanline_offset;
> > @@ -1463,6 +1489,7 @@ void skl_wm_get_hw_state(struct drm_device *dev);
> >  void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv,
> >  			  struct skl_ddb_allocation *ddb /* out */);
> >  uint32_t ilk_pipe_pixel_rate(const struct intel_crtc_state *pipe_config);
> > +bool ilk_disable_lp_wm(struct drm_device *dev);
> >  
> >  /* intel_sdvo.c */
> >  bool intel_sdvo_init(struct drm_device *dev,
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index c209a69..29d725e 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -2265,6 +2265,29 @@ static void skl_setup_wm_latency(struct drm_device *dev)
> >  	intel_print_wm_latency(dev, "Gen9 Plane", dev_priv->wm.skl_latency);
> >  }
> >  
> > +static bool ilk_validate_pipe_wm(struct drm_device *dev,
> > +				 struct intel_pipe_wm *pipe_wm)
> > +{
> > +	/* LP0 watermark maximums depend on this pipe alone */
> > +	const struct intel_wm_config config = {
> > +		.num_pipes_active = 1,
> > +		.sprites_enabled = pipe_wm->sprites_enabled,
> > +		.sprites_scaled = pipe_wm->sprites_scaled,
> > +	};
> > +	struct ilk_wm_maximums max;
> > +
> > +	/* LP0 watermarks always use 1/2 DDB partitioning */
> > +	ilk_compute_wm_maximums(dev, 0, &config, INTEL_DDB_PART_1_2, &max);
> > +
> > +	/* At least LP0 must be valid */
> > +	if (!ilk_validate_wm_level(0, &max, &pipe_wm->wm[0])) {
> > +		DRM_DEBUG_KMS("LP0 watermark invalid\n");
> > +		return false;
> > +	}
> > +
> > +	return true;
> > +}
> > +
> >  /* Compute new watermarks for the pipe */
> >  static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
> >  			       struct drm_atomic_state *state)
> > @@ -2279,10 +2302,6 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
> >  	struct intel_plane_state *sprstate = NULL;
> >  	struct intel_plane_state *curstate = NULL;
> >  	int level, max_level = ilk_wm_max_level(dev);
> > -	/* LP0 watermark maximums depend on this pipe alone */
> > -	struct intel_wm_config config = {
> > -		.num_pipes_active = 1,
> > -	};
> >  	struct ilk_wm_maximums max;
> >  
> >  	cstate = intel_atomic_get_crtc_state(state, intel_crtc);
> > @@ -2305,21 +2324,18 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
> >  			curstate = to_intel_plane_state(ps);
> >  	}
> >  
> > -	config.sprites_enabled = sprstate->visible;
> > -	config.sprites_scaled = sprstate->visible &&
> > +	pipe_wm->pipe_enabled = cstate->base.active;
> > +	pipe_wm->sprites_enabled = sprstate->visible;
> > +	pipe_wm->sprites_scaled = sprstate->visible &&
> >  		(drm_rect_width(&sprstate->dst) != drm_rect_width(&sprstate->src) >> 16 ||
> >  		drm_rect_height(&sprstate->dst) != drm_rect_height(&sprstate->src) >> 16);
> >  
> > -	pipe_wm->pipe_enabled = cstate->base.active;
> > -	pipe_wm->sprites_enabled = config.sprites_enabled;
> > -	pipe_wm->sprites_scaled = config.sprites_scaled;
> > -
> >  	/* ILK/SNB: LP2+ watermarks only w/o sprites */
> >  	if (INTEL_INFO(dev)->gen <= 6 && sprstate->visible)
> >  		max_level = 1;
> >  
> >  	/* ILK/SNB/IVB: LP1+ watermarks only w/o scaling */
> > -	if (config.sprites_scaled)
> > +	if (pipe_wm->sprites_scaled)
> >  		max_level = 0;
> >  
> >  	ilk_compute_wm_level(dev_priv, intel_crtc, 0, cstate,
> > @@ -2328,12 +2344,8 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
> >  	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
> >  		pipe_wm->linetime = hsw_compute_linetime_wm(dev, cstate);
> >  
> > -	/* LP0 watermarks always use 1/2 DDB partitioning */
> > -	ilk_compute_wm_maximums(dev, 0, &config, INTEL_DDB_PART_1_2, &max);
> > -
> > -	/* At least LP0 must be valid */
> > -	if (!ilk_validate_wm_level(0, &max, &pipe_wm->wm[0]))
> > -		return -EINVAL;
> > +	if (!ilk_validate_pipe_wm(dev, pipe_wm))
> > +		return false;
> >  
> >  	ilk_compute_wm_reg_maximums(dev, 1, &max);
> >  
> > @@ -2358,6 +2370,59 @@ static int ilk_compute_pipe_wm(struct intel_crtc *intel_crtc,
> >  }
> >  
> >  /*
> > + * Build a set of 'intermediate' watermark values that satisfy both the old
> > + * state and the new state.  These can be programmed to the hardware
> > + * immediately.
> > + */
> > +static int ilk_compute_intermediate_wm(struct drm_device *dev,
> > +				       struct intel_crtc *intel_crtc,
> > +				       struct intel_crtc_state *newstate)
> > +{
> > +	struct intel_pipe_wm *a = &newstate->wm.intermediate;
> > +	struct intel_pipe_wm *b = &intel_crtc->wm.active.ilk;
> > +	int level, max_level = ilk_wm_max_level(dev);
> > +
> > +	/*
> > +	 * Start with the final, target watermarks, then combine with the
> > +	 * currently active watermarks to get values that are safe both before
> > +	 * and after the vblank.
> > +	 */
> > +	*a = newstate->wm.optimal.ilk;
> > +	a->pipe_enabled |= b->pipe_enabled;
> > +	a->sprites_enabled |= b->sprites_enabled;
> > +	a->sprites_scaled |= b->sprites_scaled;
> > +
> > +	for (level = 0; level <= max_level; level++) {
> > +		struct intel_wm_level *a_wm = &a->wm[level];
> > +		const struct intel_wm_level *b_wm = &b->wm[level];
> > +
> > +		a_wm->enable &= b_wm->enable;
> > +		a_wm->pri_val = max(a_wm->pri_val, b_wm->pri_val);
> > +		a_wm->spr_val = max(a_wm->spr_val, b_wm->spr_val);
> > +		a_wm->cur_val = max(a_wm->cur_val, b_wm->cur_val);
> > +		a_wm->fbc_val = max(a_wm->fbc_val, b_wm->fbc_val);
> > +	}
> > +
> > +	/*
> > +	 * We need to make sure that these merged watermark values are
> > +	 * actually a valid configuration themselves.  If they're not,
> > +	 * there's no safe way to transition from the old state to
> > +	 * the new state, so we need to fail the atomic transaction.
> > +	 */
> > +	if (!ilk_validate_pipe_wm(dev, a))
> > +		return -EINVAL;
> > +
> > +	/*
> > +	 * If our intermediate WM are identical to the final WM, then we can
> > +	 * omit the post-vblank programming; only update if it's different.
> > +	 */
> > +	if (memcmp(a, &newstate->wm.optimal.ilk, sizeof *a) != 0)
> > +		newstate->wm.need_postvbl_update = false;
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> >   * Merge the watermarks from all active pipes for a specific level.
> >   */
> >  static void ilk_merge_wm_level(struct drm_device *dev,
> > @@ -2369,9 +2434,7 @@ static void ilk_merge_wm_level(struct drm_device *dev,
> >  	ret_wm->enable = true;
> >  
> >  	for_each_intel_crtc(dev, intel_crtc) {
> > -		const struct intel_crtc_state *cstate =
> > -			to_intel_crtc_state(intel_crtc->base.state);
> > -		const struct intel_pipe_wm *active = &cstate->wm.optimal.ilk;
> > +		const struct intel_pipe_wm *active = &intel_crtc->wm.active.ilk;
> >  		const struct intel_wm_level *wm = &active->wm[level];
> >  
> >  		if (!active->pipe_enabled)
> > @@ -2519,15 +2582,13 @@ static void ilk_compute_wm_results(struct drm_device *dev,
> >  
> >  	/* LP0 register values */
> >  	for_each_intel_crtc(dev, intel_crtc) {
> > -		const struct intel_crtc_state *cstate =
> > -			to_intel_crtc_state(intel_crtc->base.state);
> >  		enum pipe pipe = intel_crtc->pipe;
> > -		const struct intel_wm_level *r = &cstate->wm.optimal.ilk.wm[0];
> > +		const struct intel_wm_level *r = &intel_crtc->wm.active.ilk.wm[0];
> >  
> >  		if (WARN_ON(!r->enable))
> >  			continue;
> >  
> > -		results->wm_linetime[pipe] = cstate->wm.optimal.ilk.linetime;
> > +		results->wm_linetime[pipe] = intel_crtc->wm.active.ilk.linetime;
> >  
> >  		results->wm_pipe[pipe] =
> >  			(r->pri_val << WM0_PIPE_PLANE_SHIFT) |
> > @@ -2734,7 +2795,7 @@ static void ilk_write_wm_values(struct drm_i915_private *dev_priv,
> >  	dev_priv->wm.hw = *results;
> >  }
> >  
> > -static bool ilk_disable_lp_wm(struct drm_device *dev)
> > +bool ilk_disable_lp_wm(struct drm_device *dev)
> >  {
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> >  
> > @@ -3610,19 +3671,15 @@ static void skl_update_wm(struct drm_crtc *crtc)
> >  	dev_priv->wm.skl_hw = *results;
> >  }
> >  
> > -static void ilk_program_watermarks(struct intel_crtc_state *cstate)
> > +static void ilk_program_watermarks(struct drm_i915_private *dev_priv)
> >  {
> > -	struct drm_crtc *crtc = cstate->base.crtc;
> > -	struct drm_device *dev = crtc->dev;
> > -	struct drm_i915_private *dev_priv = to_i915(dev);
> > +	struct drm_device *dev = dev_priv->dev;
> >  	struct intel_pipe_wm lp_wm_1_2 = {}, lp_wm_5_6 = {}, *best_lp_wm;
> >  	struct ilk_wm_maximums max;
> >  	struct intel_wm_config *config = &dev_priv->wm.config;
> >  	struct ilk_wm_values results = {};
> >  	enum intel_ddb_partitioning partitioning;
> >  
> > -	to_intel_crtc(crtc)->wm.active.ilk = cstate->wm.optimal.ilk;
> > -
> 
> :) So even you yourself NAKed the previous patch.
> 
> >  	ilk_compute_wm_maximums(dev, 1, config, INTEL_DDB_PART_1_2, &max);
> >  	ilk_wm_merge(dev, config, &max, &lp_wm_1_2);
> >  
> > @@ -3645,26 +3702,29 @@ static void ilk_program_watermarks(struct intel_crtc_state *cstate)
> >  	ilk_write_wm_values(dev_priv, &results);
> >  }
> >  
> > -static void ilk_update_wm(struct drm_crtc *crtc)
> > +static void ilk_initial_watermarks(struct intel_crtc_state *cstate)
> >  {
> > -	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
> > -	struct intel_crtc_state *cstate = to_intel_crtc_state(crtc->state);
> > +	struct drm_i915_private *dev_priv = to_i915(cstate->base.crtc->dev);
> > +	struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
> >  
> > -	WARN_ON(cstate->base.active != intel_crtc->active);
> > +	mutex_lock(&intel_crtc->wm.wm_mutex);
> > +	intel_crtc->wm.active.ilk = cstate->wm.intermediate;
> > +	ilk_program_watermarks(dev_priv);
> > +	mutex_unlock(&intel_crtc->wm.wm_mutex);
> > +}
> >  
> > -	/*
> > -	 * IVB workaround: must disable low power watermarks for at least
> > -	 * one frame before enabling scaling.  LP watermarks can be re-enabled
> > -	 * when scaling is disabled.
> > -	 *
> > -	 * WaCxSRDisabledForSpriteScaling:ivb
> > -	 */
> > -	if (cstate->disable_lp_wm) {
> > -		ilk_disable_lp_wm(crtc->dev);
> > -		intel_wait_for_vblank(crtc->dev, intel_crtc->pipe);
> > -	}
> > +static void ilk_optimize_watermarks(struct intel_crtc_state *cstate)
> 
> I don't really like that name. Should just have foo_pre and foo_post or
> something along those lines IMO.

My thinking was actually the opposite...things like foo_pre() and
foo_post() are a bit opaque/meaningless to anyone who doesn't know the
intimate details of a specific platform's watermark handling, whereas
"initial_watermarks" and "optimize_watermarks" give a little bit more
indication of why we're bothing to program stuff twice and how they
differ.  I don't feel super strongly about it though, so I can change
the names to something else if you feel it makes more sense.

I guess ultimately the important thing is to split this all out into its
own files and write some detailed kerneldocs on it all; that's supposed
to be my next task anyway.


Matt

> 
> > +{
> > +	struct drm_i915_private *dev_priv = to_i915(cstate->base.crtc->dev);
> > +	struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
> >  
> > -	ilk_program_watermarks(cstate);
> > +	mutex_lock(&intel_crtc->wm.wm_mutex);
> > +	if (cstate->wm.need_postvbl_update) {
> > +		intel_crtc->wm.active.ilk = cstate->wm.optimal.ilk;
> > +		ilk_program_watermarks(dev_priv);
> > +		cstate->wm.need_postvbl_update = false;
> > +	}
> > +	mutex_unlock(&intel_crtc->wm.wm_mutex);
> >  }
> >  
> >  static void skl_pipe_wm_active_state(uint32_t val,
> > @@ -6970,9 +7030,11 @@ void intel_init_pm(struct drm_device *dev)
> >  		     dev_priv->wm.spr_latency[1] && dev_priv->wm.cur_latency[1]) ||
> >  		    (!IS_GEN5(dev) && dev_priv->wm.pri_latency[0] &&
> >  		     dev_priv->wm.spr_latency[0] && dev_priv->wm.cur_latency[0])) {
> > -			dev_priv->display.update_wm = ilk_update_wm;
> >  			dev_priv->display.compute_pipe_wm = ilk_compute_pipe_wm;
> > -			dev_priv->display.program_watermarks = ilk_program_watermarks;
> > +			dev_priv->display.compute_intermediate_wm =
> > +				ilk_compute_intermediate_wm;
> > +			dev_priv->display.initial_watermarks = ilk_initial_watermarks;
> > +			dev_priv->display.optimize_watermarks = ilk_optimize_watermarks;
> >  		} else {
> >  			DRM_DEBUG_KMS("Failed to read display plane latency. "
> >  				      "Disable CxSR\n");
> > -- 
> > 2.1.4
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Ville Syrjälä
> Intel OTC

-- 
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795


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